A combination of Polypodium leucotomos extract with vitamin A, vitamin C and selenium as an immune adjuvant against recurrent infections oleh Alejandra Visedo Colino, Flavia Tamara Hernández Rocamora, José Pardo Zapata, Julio Gosálbez, María del Mar Ortega-Villaizán Romo, Regla Maria Medina-Gali, David González Fernández, Alejandro Pérez-Fernández